docs: def config_collection(self):
  		"""Collect core config from config files for all seen modules.
  		"""
  		shutit_global.shutit_global_object.yield_to_draw()
  		self.log('In config_collection',level=logging.DEBUG)
  		cfg = self.cfg
  		for module_id in self.module_ids():
  			# Default to None so we can interpret as ifneeded
  			self.get_config(module_id, 'shutit.core.module.build', None, boolean=True, forcenone=True)
  			self.get_config(module_id, 'shutit.core.module.remove', False, boolean=True)
  			self.get_config(module_id, 'shutit.core.module.tag', False, boolean=True)
  			# Default to allow any image
  			self.get_config(module_id, 'shutit.core.module.allowed_images', [".*"])
  			module = self.shutit_map[module_id]
  			cfg_file = os.path.dirname(get_module_file(self,module)) + '/configs/build.cnf'
  			if os.path.isfile(cfg_file):
  				# use self.get_config, forcing the passed-in default
  				config_parser = ConfigParser.ConfigParser()
  				config_parser.read(cfg_file)
  				for section in config_parser.sections():
  					if section == module_id:
  						for option in config_parser.options(section):
  							if option == 'shutit.core.module.allowed_images':
  								override = False
  								for mod, opt, val in self.build['config_overrides']:
  									val = val # pylint
  									# skip overrides
  									if mod == module_id and opt == option:
  										override = True
  								if override:
  									continue
  								value = config_parser.get(section,option)
  								if option == 'shutit.core.module.allowed_images':
  									value = json.loads(value)
  								self.get_config(module_id, option, value, forceask=True)
  			# ifneeded will (by default) only take effect if 'build' is not
  			# specified. It can, however, be forced to a value, but this
  			# should be unusual.
  			if cfg[module_id]['shutit.core.module.build'] is None:
  				self.get_config(module_id, 'shutit.core.module.build_ifneeded', True, boolean=True)
  				cfg[module_id]['shutit.core.module.build'] = False
  			else:
  				self.get_config(module_id, 'shutit.core.module.build_ifneeded', False, boolean=True)